1. Technical Field
The invention relates to semiconductors and the fabrication thereof. In particular, the invention relates to imprint lithography used to define one or both of micro-scale and nano-scale structures during semiconductor fabrication.
2. Description of Related Art
A relatively new lithographic methodology that attempts to address many of the challenges associated with practical implementation and commercial acceptance of nanotechnology is imprint lithography. Unlike conventional optical lithography that generally relies on indirect, mask-based patterning of samples or substrates during fabrication, imprint lithography directly patterns the substrate using a mold. Specifically, the mold is employed to ‘print’ a fabrication pattern directly onto the substrate. The mold may be fabricated using conventional lithographic methodologies and then is employed to rapidly ‘print’ one or more copies of the fabrication pattern onto a single substrate and/or onto multiple substrates.
Unfortunately, the practical use of imprint lithography has been limited by a need to align the mold with the substrate to be imprinted and then separately, typically in a different apparatus, imprint the mold pattern onto the substrate. For example, a conventional mask aligner may be employed to align the mold with the substrate. After alignment, the mold and the substrate are transferred to a press for imprinting. Such transfer of the aligned mold and substrate can and generally does adversely affect an accuracy of the alignment. In addition, imprint uniformity may be limited by both the transfer and an inability to accurately control a pressure with which the mold is pressed into the substrate by the press.
Accordingly, it would be desirable to have an approach to imprint lithography that did not require a transfer from one apparatus to another. Moreover, it would be beneficial if such approach to imprint lithography also maintained alignment accuracy and facilitated imprint uniformity. Such an imprint lithography approach would solve a long-standing need in the area of nanotechnology.